1. Cook onion and potatoes in a medium sized pan in about 1 tablespoon olive oil.
2. After 4 minutes, add beans, diced chilies, cumin and chili powder. Saute for about 10 minutes, until potatoes are soft.
3. Once potato/bean mix is done, fill taco shells/tortillas with the bean/potato mix, lettuce, tomatoes, guacamole and salsa.
Source of recipe: I made it up.